Pawl-and-ratchet mechanism



UNITED STATES PATENT OFFICE.

OSCAR WCODWARCD, OF BABYLON, NEW YORK, ASSIGNOR '1'0 REMINGTONTYPEWRITER COMPANY, OF ILION, NEW YORK. A COBPORATZON OF NEW YORK.

PAWL-QAND-BATCHET MECHANISM.

Original application filed May 29, 1919,

To all whom it may concern Be it known that 1, OSCAR vVooDWARo, citizenof the United States, and resident of Babylon, in the county of Suffolk,and State of New York, have invented certain new and useful Improvementsin Pawl-and- Ratchet Mechanism, of which the following is aspecification.

My invention relates to pawl and ratchet mechanism, and moreparticularly to the returning spring for and its connection with thepawl.

The main object of my invention, generally stated, is to providesimpleand reliable means of the character specified.

To the above and other ends which will hereinafter appear, my inventionconsists in the features of construction, arrangements of parts, andcombinations of devices set forth in the following description-andparticularly pointed out in the appended claims.

In the accompanying drawings wherein like reference characters representcorresponding parts in the various views,

Figure 1 is an enlarged detail vertical fore-and-aft sectional View ofpart of a typewriter construction including the present invention, thesection being taken on the line m--w of Fig. 2 and looking in thedirection of the arrow atsaid' line.

Fig. 2 is an enlarged detail fragmentary transverse sectional viewshowing the parts illustrated'in Fig. 1, the section beingtaken on theline y-y of Fig. 1 and looking in.

the direction of the arrow at said line.

Fig. 3 isa detached detailed perspective view of the spring and pawl.

l have shown my invention in the present instance embodied in atypewriting machine and included in the pawl and ratchet mechanismbetween the escapement wheel and feed pinion where it is particularlyavailable. It

' should be understood, however, that the invention may be embodied inother relations and moreespecially where the pawl 1s confined within acomparatively small space and but little room is provided for the use ofa spring mounted and connected in the usual manner.

This case is a division of my application Serial No. 300,571 filed May29, 1919, and parts disclosed and not claimed herein are claimed in saidapplication.

Specification of Letters Patent.

Serial No. 300,571. 1920. Serial No. 868,839.

. its embodiment therein.

Patented Mar. 15, 1921.

Divided and this application filed March 26,

In the accompanying drawings I have shown only so much of a typewritingma- (111116 as be necessary to arrive at an understanding of the presentinvention in The power driven carriage (not shown) travels over the topplate 1 of the machine and carries a feed rack2 which meshes with a feedpinion 3. This pinion forms part of a sleeve at which is mounted andadapted to turn with a shaft 5 in one direction and to be turnedindependently thereof in the oppo site direction, as will hereinaftermore clearly appear. he shaft 5 is reduced at its ends to form bearingportions 6 and 7, the former of which receives its support in a bearingopening in a bracket arm 8 carried by a bracket supported by the topplate of the machine. The parts 7 of the shaft receive their support ina bearing sleeve 9 adjustably secured to an arm 10 formed as a part ofthe same bracket from which the arm 8 projects. An escapement wheel 11is fixed to a hub-like supporting member 12 by screws 13, and saidhub-like member is in turn secured to the shaft 5 by a screw 1%. Fixedto and projecting from the forward face of the member 12 are two pins 15and lo the latter of which constitutes a pivot on which a pawl 16 issupported and mounted to turn. The pin 15 constitutes an anchorage forone end of a bowed wire C- spring 17, which as shown is a contractionspring substantially semi-circular in form and is tensioncd so that thefree end of the spring tends to be drawn toward the anchored end.thereof. The tail of the pawl 16 is provided with an enlarged opening 18adapted to receive the free end 19 of the spring 17, said end 19 beingpin-like and formed by substantially rectangular bend the wire so thatthe part 19 of the spring extends axially of the hole 18 in the pawl andalso in the direction of the anchorage 15'of the spring. The diameter ofthe opening 18 is materially greater than the diameof the wire fromwhich the spring is conned so that the spring bears only at one ndagainst the pawl and against the bottom wall 20 of the opening 18. Thisbottom wall preferably slopes from its outer edges to the center, formina depression which centers the free end OI the spring in the opening.The spring is thus maintained free from v with the pivotal movement ofthe pawl to engaging position. The power exerted by the spring on thepawl, it will be observed, 7

is almost in direct line with the anchored end of-the spring and forcesthe nose 21 of the pawl between the teeth 22 of a wheel 23 and intoeffective engagement with the inner faces 24 of said teeth 22. The partsthus act as a pawl and ratchet mechanism that causes the escapementwheel 11 to turn with the-wheel 23 in one direction and enables thewheel 23 to turn independently of the es capement wheel when the formeris turned in the opposite direction. As shown in the present instance,the toothed wheel 23 is in the nature of a double wheel formed integralwith the sleeve l. Thus the flange 25 on the sleeve is formed with acircular rim projecting from one side thereof and from which the teeth22 are formed. This rim provides a recess in one side of the wheel 23and is out completely throu 'h the thickness thereof as indicated at26,- forming the outwardly extending ratchet teeth 22 for 3 operationwith a back spacing pawl 27 and by which the wheel 23 is turned back,whereas the inner end portions 24; of the teeth form internal teeth, sotospeak, for cooperation with the pawl 16 contained within the wheel. Itis in this sense that T havereferred to the wheel 23 as a double wheel,one pawl 27 co-acting with the teeth from the outside and the other pawl16 co-acting with the teeth from inside the wheel. Although the spring17 and pawl 16 are housed and confined within the comparatively smallspace within the wheel 23, a strong pawl and effective spring may beemployed within said space and between the feed pinion 3 and theescapement wheel 11, the spring passing from the pawl at one side of theshaft to the pinat the opposite side thereof where the spring is bent tosurround the pin and receive a very slight pivotal movement thereonduring the action of the pawl.

The back spacing pawl 27, as shown, is

pivoted at 28 to a carrier 29 which in turn is pivoted at 30 to abracket 31, the carrier being returned to normal position by a spring32. A key controlled link 33 is pivoted at 34 to the pawl 27. An upwardmovement of the link 33 under control of its key is effective first toturn the pawl 27 on its pivot 28 and bring the engaging nose 27 thereofinto engagement with the teethof the wheel 23 and then move the pawl 27and wheel together, the pawl at this time moving with its carrier 29around the pivot 30, thus effecting a back space movement of the wheel23 and feed pinion 3, while the eS- Inassembling the parts' the, pawl 16is introduced into position on its pivot pin 15 and the spring isreadily connected therewith in the manner shown. When the combinedwheel'23, sleeve 5 and feed pinion 3 are introduced into position on theshaft and the parts mounted in place as shown, the pawl and spring areinclosed within the wheel 23 and the pawl is prevented frombeing'displaced from its pivot.

What I claim as new'and desire to secure by Letters Patent, is

-l. The combination of a pivoted pawl having a hole therein, and abow-spring tensioned to draw the ends of the spring one toward theother, one end of the spring being connected to a relatively fixed partwhile the other end is formedwith a pin-like portion that enters saidhole and bears only at itspoint and only againstthe bottom of the hole.V

2. The-combination of a wheel having a recess therein and teeth thereon,a pawl contained within said recess, and a substantially semi-circularcontraction spring hearing at an extreme end only against said pawl atone'side of the axis of the wheel" and connected at the other end to arelatively fixed part at the diametrically opposite sidev of the axis ofthe wheel, said spring being tensioned to exert a force which tends todraw the two ends of the spring toward each other in a line through theaxis of the wheel. 7

3. The combination of a pawlhaving an opening therein, and asubstantially semicircular springwhioh exerts'a force to move the pawlinto engagement with the part with draw the ends ofjthespring towardeach other, one end portion of'the spring being loosely received in' theopeningin the pawl andseated therein only with a point hearing, theother end of the spring being conc-spring that has a point bearing onlyat,

one end against the pawl and exerts its force to draw said end of thespring toward its other anchored end thereof,

110 whichit co-acts and which is tensioned to I 6. The combination of apawl having an opening therein, and a C-spring of smaller diameter thansaid opening and bearing at one end against the bottom wall thereofwhich is formed to center the coacting end portion of the spring in andmaintain it free from contact with the side walls of the opening.

7. The combination of a pawl, and a C- spring that bears at one endagainst the pawl and which is mounted at its opposite anchored end toreceive a slight pivotal movement.

8. The combination of a wheel comprising a disk portion having exteriorteeth and a circular off-set rim forming a recess, said rim being cutthrough to provide a series of interior teeth, a pivoted pawl having anenlarged hole therein and adapted to engage said interior teeth, and aC-shaped spring having an angular bend at one termination, the extremityof which bears endwise at the bottom of said enlarged hole in the pawl.

Signed at the borough of Manhattan, city of New York, in the county ofNew York and State of New York this 24th day of March, A. D. 1920.

OSCAR WOODWARD.

Vitnesses CHARLES E. SMITH, E. M. lVELLs.

